The Fifth Amendment: Self-Incrimination and the Brain

Abstract

This Fifth Amendment’s self-incrimination clause has been at the center of constitutional discussions over neuroimaging’s future. That it is not because it clearly would apply to neuroimaging – but rather because neuroimaging raises a easily formulated (albeit difficult to answer) Fifth Amendment puzzle: It seems to count as both of what are supposed to be two mutually exclusive categories in Fifth Amendment law, because it is both like a witness statement (or “testimonial”) and like physical evidence such as blood flow or other physiological processes. This chapter explores various solutions scholars have proposed to this puzzle, rooted in distinctive theories of the self-incrimination clause – and the unanswered questions each of these theories raises. It also emphasizes another point that has received less attention in discussions of self-incrimination and neuroimaging: idea that Fifth Amendment protection for our thoughts and other mental process should perhaps sometimes cover the biology underlying that thinking even when government plausibly claims it wants access to it for reasons other than inferring our thoughts or beliefs.